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7594952 Treatment of smelting by-products  
A method of treating a spent potliner after use in an aluminum smelting process, the method comprising crushing and classifying the spent potliner, placing the classified and crushed spent potliner...
6884428 Use of reinforced foam implants with enhanced integrity for soft tissue repair and regeneration  
A biocompatible tissue repair stimulating implant or “scaffold” device is used to repair tissue injuries, particularly injuries to ligaments, tendons, and nerves. Such implants are especially...
6846418 Process for treating acidic and metallic waste water  
A process for treating acidic and metallic waste water, particularly the rinsing water and/or used acids from pickling plants. The process includes the step of adding an alkaline solution or gas to...
6821351 Hydrofluoric acid generating composition and method of treating surfaces  
The present invention relates to compositions, kits and processes for the brightening of metal surfaces by the application of the chemical compositions. These compositions act to release...
6660893 Hydrogen fluoride recovery process  
A process for separating and recovering hydrogen fluoride from a mixture with an organic compound especially a fluorine-containing compound by extraction with a solution of an alkali metal fluoride...
6605193 Recovery of HFC-32  
A method for isolating 32 from a crude mixture containing HCl and an azeotropic mixture of 32 and HF is provided without the need to isolate any HF azeotrope.
6428764 Process for the production of calcium fluoride  
A process is disclosed for producing calcium fluoride. The process comprises (a) mixing phosphate rock with aqueous H 2 SiF 6 at ambient temperature for at least one hour; (b) nucleating the...
6423290 Method for recovering an organic solvent from an acidic waste stream such as in integrated chip manufacturing  
An organic solvent is separated from a waste stream comprising hydrofluoric acid, an organic solvent and etchant contaminants. The process comprises separating the hydrofluoric acid by subjecting...
6375915 Method of regenerating a spent pickling solution  
In a method of regenerating a spent pickling solution composed of nitric acid and hydrofluoric acid and containing metal fluorides and metal nitrates, the pickling solution is heated in a reactor...
6350425 On-site generation of ultra-high-purity buffered-HF and ammonium fluoride  
Provided is a novel method and system for preparing ultra-high-purity buffered-hydrofluoric acid or ammonium fluoride controlled concentration The method comprises bubbling purified ammonia vapor...
6346227 Process for preparing pure hydrofluoric acid  
The novel process for preparing pure hydrofluoric acid or pure hydrogen fluoride is characterized in that, after pretreatment by distillatioil/oxidation, a two-stage scrub is carried out using...
6224844 Process for the production of calcium fluoride  
A process is disclosed for producing calcium fluoride comprising: (a) mixing aqueous H 3 PO 4 with aqueous H 2 SiF 6 to form a mixture such that the concentration of H 3 PO 4 is at least...
6217840 Production of fumed silica  
A method for producing fumed silica and a fluorine-containing product from a source of silica in solid form and a solid material containing fluorine, the solid material selected from the group...
6217836 Recovering carbon, silica and alumina from spent potliner  
Spent potliner from aluminum reduction cells is treated, for example, with sulfuric acid to recover carbon, silica and alumina or to recover a vitrified product of silca and alumina.
6207125 Recycling of flux material  
Flux residues from aluminium soldering fluxes composed of alkali metal metallates, especially fluoroaluminates of the alkali metals, in particular potassium and cesium, can be recycled by adding...
6193944 Method of recovering fumed silica from spent potliner  
Spent potliner from an aluminum reduction cell is subject to an acid digest and the digest may be adjusted to produce a first gas component comprised of at least one material selected from the...
6187275 Recovery of AlF3 from spent potliner  
A method of recovering AlF 3 from spent potliner using an acid digest to form gaseous HF which is converted to hydrofluoric acid and reacted with alumina trihydrate to form AlF 3 .
6183720 Process and apparatus for producing high-purity chemicals for the microelectronics industry  
A process for producing a high-purity liquid chemical is provided. A chemical gas is successively purified over first and second purification columns by passing, countercurrently, a scrubbing...
6177058 Hydrogen fluoride compositions  
The present invention provides compositions that are intimate mixtures of hydrogen fluoride and a polymer. The compositions of the invention are less hazardous and, therefore, more conveniently...
6123908 Method of treating spent potliner material from aluminum reduction cells  
A process of treating spent potliner material from aluminum reduction cells and recovering useful products. In the process of the present invention, spent potliner material is introduced into an...
6015477 Point-of-use ammonia purification for electronic component manufacture  
Highly purified ammonia for use in processes for the production of high-precision electronic components is prepared on-site by drawing ammonia vapor from a liquid ammonia reservoir, passing the...
5980850 Process and plant for extraction or recovery of acids from solutions of these acids  
Process for extraction or recovery of acids, in particular hydrofluoric acid, hydrochloric acid and nitric acid, from solutions of these acids containing metal, by pyrohydrolytic treatment and...
5948381 Process for separating fluorocarbon compounds  
The invention provides a process for separating fluorinated organic compounds from mixtures of the such compounds and hydrogen fluoride. More particularly, the invention provides a method for...
5800795 Hydrogen fluoride recovery process  
Process for the recovery of hydrogen fluoride (HF) from a mixture, preferably an azeotropic mixture, of HF with water and/or an organic compound such as 134a, 125 or 133a, which comprises...
5766483 Process for hydrogen fluoride separation  
A method for separating hydrogen fluoride from a chemical mixture is provided. In the process of the invention, hydrogen fluoride is separated from a chemical mixture containing hydrogen fluoride...
5632966 Process for hydrogen fluoride separation  
The present invention provides a convenient method for separating hydrogen fluoride from a chemical mixture. More specifically, a method is provided in which hydrogen fluoride is separated from a...
5597545 Recovery of HF from aqueous streams  
HF can be recovered from aqueous streams, particularly those which are dilute and have a concentration of HF lower than the azeotrope between HF and water. Such aqueous streams are contacted with...
5585085 Removal of water and/or hydrocarbons from hydrogen fluoride  
A process for removing water and/or carbon compounds from hydrogen fluoride by contacting the hydrogen fluoride to be purified with elemental fluorine.
5560899 Process for separating HF from its mixtures with hydrochlorofluorocarbons 123 and/or 124  
The invention relates to a process for separating HF contained in liquid mixtures comprising HCFC 123 and/or 124. The mixtures, enriched in C 2 Cl 4 up to a content of such compound of 20-75% by...
5457267 Process for disposing of halons or halon-containing fluorocarbons or chlorofluorocarbons  
A process for disposing of bromofluorocarbons, bromochlorofluorocarbons, or mixtures of any of bromofluorocarbons, bromochlorofluorocarbons, fluorocarbons, or chlorofluorocarbons. The process...
5411726 Process for purifying hydrogen fluoride  
The invention relates to a process for purifying industrial anhydrous hydrogen fluoride by means of oxygen difluoride.
5362469 Preparation of ultrapure hydrogen fluoride  
A process for preparing ultrapure hydrogen fluoride by contacting impure hydrogen fluoride with elemental fluorine in the presence of metal fluorides. The ultrapure hydrogen fluoride which can be...
5348722 Removal of detrimental metal ions from hydrofluoric acid solution for cleaning silicon surfaces  
The invention relates to the removal of detrimental metal ions represented by Cu ion from a hydrofluoric acid solution for use in the manufacturing of semiconductor devices to clean silicon wafer...
5346684 Recovery of anhydrous hydrogen fluoride from depleted uranium hexafluoride  
A method is provided for recovering an anhydrous hydrogen fluoride product from uranium hexafluoride gas by initially reacting the uranium hexafluoride in a primary reactor with steam to produce a...
5304522 Liquid acid regeneration method  
A process is disclosed for regenerating a spent liquid acid catalyst comprising the steps of: (a) providing a spent liquid acid catalyst comprising HF, sulfolane, and conjunct polymeric...
5284605 Method of treating gas based on electrolytic fluorine containing uranium compounds  
A method of treating a gas based on fluorine and containing hydrofluoric acid, and which may optionally contain condensable gaseous compounds, especially uranium compounds, and non-condensable...
5219551 Process for preparing hydrogen fluoride  
A process for preparing hydrogen fluoride, which comprises (i) reacting calcium fluoride with sulfuric acid to produce a gypsum and a gas containing hydrogen fluoride, (ii) separating hydrogen...
5164174 Detoxification of aluminum spent potliner by thermal treatment, lime slurry quench and post-kiln treatment  
A method is disclosed for detoxification of aluminum spent potliner by thermal treatment in a rotary kiln while blended with limestone and metal silicates to destroy cyanides and convert the...
5149515 Process for the production or recovery of acids from metalliferous solutions of such acids  
During the pickling, etching, chemical shaping etc. of steels, stainless steels, special alloys and special metals and the dissolution of those metals, metalliferous solutions of the acids employed...
5108559 Process for purifying hydrogen fluoride  
A process for manufacturing high purity anhydrous hydrogen fluoride (HF) having low levels of oxidizable impurities by electrolytically oxidizing the impurities. Specifically, trivalent arsenic...
5100639 Process for purifying hydrogen fluoride  
A process for manufacturing high purity anhydrous hydrogen fluoride (HF) having low levels of oxidizable impurities by electrolytically oxidizing the impurities. Specifically, trivalent arsenic...
5094773 Azeotropes of HF and process for the separation of HF via azeotropic distillation  
Azeotropes of HF and 2,2-dichloro-1,1,1-trifluoroethane and of HF and 2-chloro-1,1,1,2-tetrafluoroethane. Process for the separation of hydrogen fluoride (HF), 2,2-dichloro-1,1,1-trifluoroethane...
5089241 Process for converting hexafluoroarsenic acid or any salt thereof to arsenic acid or salt thereof which can then be rendered nonhazardous  
The present invention provides a process for the conversion of hazardous hexafluoroarsenic acid or any salt thereof to arsenic acid or salt thereof which can be rendered nonhazardous. In...
5047226 Process for the removal of arsenic in the manufacture of hydrofluoric acid  
There is disclosed a process wherein impurities are removed from hydrofluoric acid by converting the highly volatile arsenic compounds into a compound with a very high boiling point. The process...
5032371 Process for the continuous recovery of hydrogen fluoride gas  
A continuous process for the recovery of anhydrous hydrogen fluoride gas by contacting an aqueous solution of an alkali metal fluoride in hydrofluoric acid with a sulfur-containing dehydrating...
4990320 Process for purifying hydrogen fluoride  
A process for preparing hydrogen fluoride that involves treating anhydrous hydrogen fluoride containing primarily trivalent arsenic impurities with an iodine compound capable of providing iodide...
4965061 Process for removing fluoride from a wastewater and producing hydrofluoric acid therefrom  
A process for producing hydrofluoric acid from SiF 6 2 - in a wastewater is disclosed. The process is carried out by (i) combining (NH 4 ) 2 SO 4 , at a pH high enough such that the sulfate is...
4954330 Process for purifying hydrogen fluoride  
A process for preparing hydrogen fluoride involving treating anhydrous hydrogen fluoride containing primarily trivalent arsenic impurities with an effective amount of chromium (VI) oxide (i.e., CrO...
4952386 Method and apparatus for purifying hydrogen fluoride  
A method for purifying hydrofluoric acid, comprising the steps of filtering the hydrofluoric acid to remove particulates, passing the filtered acid through a cation exchange material and an anion...
4936955 Hydrofluoric acid reprocessing for semiconductor standards  
A two-step distillation process provides semiconductor purity, concentrated hydrofluoric acid. Further, the distillation process, occurring under reduced pressures eliminates essentially pure water...
Matches 1 - 50 out of 128 1 2 3 >